<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>CSS demo</title>
    <link rel="stylesheet" href="css/main.css">
</head>
<body>
    <div class="wrap">
        <div class="sidebar">
            <h1>css demo</h1>
            <ul>
                <li data-url="demo/vertical-text">竖行文字居中</li>
                <li data-url="demo/selector/nth-child">nth-child 选择符</li>
            </ul>
        </div>
        <div class="content">
            <iframe src="demo/vertical-text" frameborder="0"></iframe>
        </div>
    </div>
    <script src="js/main.js"></script>
</body>
</html>